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Suely L. Galdino Maria C. A. Lima Alexandre J. S. Góes Ivan R. Pitta Cuong Luu-Duc 《光谱学快报》2013,46(7-8):1013-1021
In the present investigation, a study of the electron impact mass spectrometry data is reported for seven compounds of a series of some 3-(4-chlorobenzyl)-5-benzylidene-imidazolidine-2, 4-diones and 3-(4-fluoro or chlorobenzyl)-5-benzylidene-thiazolidine-2, 4-diones previously synthesized. 相似文献
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Ivan R. Pitta Claude Bosso Alexandre J. S. Góes Maria C. A. Lima Suely L. Galdino Cuong Luu-Duc 《光谱学快报》2013,46(3):419-431
In the present investigation, a study of the electron-impact mass spectrometry in positive- and negative-ion modes is reported for a series of 3-chlorobenzyl-5-benzylidene-imidazolidine-2,4-dione and -thiazolidine-2,4-dione derivatives previously synthetized. 相似文献
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New 2-(α-fluorobenzyl)benzimidazole derivatives have been prepared. Fluorination was carried out from benzylic alcohols using 2-chloro-1,1,2-trifluorotriethylamine reagent. The scope and the rates of formation of the resulting products are dependent on the nature of the substituents. Physical data, 1H and 19F NMR chemical shifts of the hydroxy and fluorine compounds are given. 相似文献
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波纹圆孔光栏的衍射及其设计 总被引:2,自引:1,他引:1
详细研究了波纹光珠菲涅耳衍射特征,提出并论证了调幅正弦波纹光栏级在较大的菲涅耳数范围内有效地抑制光束中央部分的衍射调制,并给出这类波纹光栏用于高功率光系统的设计程序。 相似文献
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Sylvain Hamman Claude Bguin Claude Charlon Cuong Luu-Duc 《Magnetic resonance in chemistry : MRC》1983,21(6):361-366
The analysis of the ABKX spectra of thirteen compounds of the series RC(H-K)(F-X)C(H-A)(H-B)X gave the four vicinal proton-proton and fluorine-proton coupling constants. These coupling constants of conformationally mobile structures were used (i) to calculate the populations of the rotational states of the ? CHF? CH2? bond, (ii) to calculate the vicinal trans proton-proton J(HH)t and gauche and trans fluorine-proton coupling constants J(FH)g and J(FH)t and (iii) to give the unambiguous assignment of protons H-A and H-B. The dependence of the gauche and trans coupling constants with substituent electronegativity is explored. The results extend known correlations towards smaller electronegativity values. More quantitatively, the results and those in the literature, excluding those where deformations of torsional or bond angles occur, give a good fit of the data: a linear fit for J(HH)t = 15.0-0.77 Σ(ΔE), an exponential fit for J(FH)g = 15.35 exp [-0.266 Σ (ΔE)] and a linear fit for J(FH)t = 65.75 - 7.52 Σ (ΔE), where Σ (ΔE) is the sum of the electronegativity difference between hydrogen and the six atoms or groups on the CH? CF fragment. 相似文献
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光纤陀螺的噪声及其实验分析 总被引:1,自引:0,他引:1
通过对FOG-110-I全光纤陀螺仪样机的研制,分析了光纤陀螺的噪声源,并对信号光背向反馈进入激光器引起的强度噪声和由光纤PZT位相调制器引起的幅度调制对光纤陀螺系统的影响作了重点分析。最后,给出了FOG-110-I全光纤陀螺样机的测试结果和实验分析。 相似文献